Process for making rubber fabric.



APPLICATION IILIID APR. 16. 1909.

Patented Jan.4,1910.

glnvcxifot 20 the cost of manufacture or the 30 of breaking 4 rial-second: no increase in 55 result from t STATES PAIENT oFFIoE.

ADNA. D. WARNER, 0F MISHAWAKA, INDIANA.

BROCESS FOR MAKING RUBBER FABRIC.

. Specification of Letters Patent.

Patented Jan. 4, 1910.

Application filed April 16, 1909. 8erii 1 i 'g,-490,228.

To all whom it may concern: I

Be it known that I, Anna D. WARNER, a

citizen of the United States, residing in Mishawaka, State of Indiana, have invented sea-certain new and useful Improvement in Processes for Making Rubber Fabric, of which the following is a specification.

The prcsent invention has relation to a process whereby rubber fabric is produced 10 and more particularly to such process as adapted to the shoes or boots.

The invention is especially useful in the production of rubber soles intended to be production of the parts of 15, applied to shoes or boots of an kind and particular-l to rubber shoes or oots. The abric pro need by my rocess is more durable than others made rom the same stock and the process does not involve increasing making of any changes in existing plants or machinery.

The rocess includes two principal features of improvement which I prefer to combine as hereinafter described, but which may be used independentlfy with good results.

The first of these eatures, which has reference to the mode of relating what I term the line of rolling of the material in different layers, has for its object the revention or checking in the abric and the utilizatlon of certain peculiarities in the molecular constitution of rubber sheets which I have discovered.

The second feature, having reference to the mode of union of the component sheets,

has for its object the entire avoidance of air cells in the completed fabric, and makes it ipossible (especially in connection with the rst named feature) to build up very thick 40. soles without danger of imperfections.

The principal advantages found in soles made acording to this process are-first: superior durability as com ared with former soles made of the same thickness and matethe cost of production-third: the soles are made and applied by existing types of machinery and therefore their manufacture involves no change in existing plants-fourth: a thicker sole is produced Without impairing the quality of the material-fifth: the various portions of the sole are individually adapted to the special wearin stresses to which they are respectivel sub ected. These advantages e principal features of improvement above alluded to.

It is obviously desirable to make rubber soles on boots and shoes as thick as possible, consistently with comfort in wearing them. The life of such soles is of roportional to such thickness, other things ein etapal. But it is found in ractice that the t 10 er a single sheet of rub er is rolled 3n calendering the greater is the proportion f air cells, and as these cells are opened by process of wear, they absorb dirt and water and cause rapid disintegration of the material. On the other hand, where soles are built up of separate calender-ed sheets united by cement, the utmost care cannot prevent formation of similar cells, due to the volatile ingredient of the rubber cement (generally benzene) permeating the mass of the rubber and producing a spongy texture by its expansion.

I have discovered that se arate calendered sheets of green or uncured rubber may be united perfectly by rolling cold under incourse roughly 1" creased pressure as compared with the calendering pressure, and that, where this process is resorted to, practicall all spongy texture is done away with. I have further discovered that by the use of this process the peculiar internalstructure of the material originally caused by the calendering rolls is not materially disturbed. This discovery has rendered possible the arran ement of the various sheets or layers as ereinafter described without sacrificing any of the advantages pointed out.

The improved sole -in its preferred form, will be described with reference to the accompanying drawings wherein- Figure 1 is a side elevation of one form of the improvedsole showing the laminae or some of them separated at one end for greater distinctness, Fig. 2 is a plan view of the under or outer face of said sole as completed, and Fig. 3 is a side elevation as completed.

Where rubber compounds are formed into sheets by ssing them between hot calendering roll sl the internal structure is modified and I have found that the following qualities are bservable. First: the tensile strength is eater in the direction in which the rolling as occurred. This direction I have termed the line of rolling. Second: the elasticity or resilienc is ater at right angles to this direction. Thi l z the tendency to split or check is greater when a sheet is bent on curves whose axis is parallel to the llU line of rolling (in other words across the It is within the scope of this invention to sheet) than when bent at right angles to this place the alternate sheets with their lines of direction. I have also discovered that where rolling crossing each other, or any other arcalendered sheets of rubber compound are rangement of crossed lines of rolling might united by cold rolling as above described, be employed without departing from this inthisinternalstructure is not interfered with vention. Where sheets are thus joined with by theexcessive pressure necessary in conlines of rolling crossed, in order to avoid nection with this process. Furthermore I distortion or change of molecular arrangehave found by practical commercial use that, ment, as well as to prevent the formation of by uniting sheets with their lines of rolling air cells within the sole, I prefer to unite '75 1 making material angles the one with the the sheets by running them together cold, in other, the advantageous qualities belonging uncured condition through laminating to each direction of the lines may be united rollers of a well known type, having a yieldas hereinafter more fullyset forth. ing pressure caused by the use ofweights 15 The articularsole shown as an example or springs. The weight or pressure used 15 in the rawings is built up as follows The four or five times as great as that employed plain sole 10, intended to receive the heel where mere cementing is to be accomplished, and tap and to be joined to the uppers, is or where sheets are united hot.

composed ofa number of laminae or sheets In building up the particular sole illus- 20 11 and12. In the particular instance illustrated, I take two sheets 11 and 12 and trated these are two in number although unite them (or a greater number if desired) more may bemsed if desired without departby the ordinary process of warm rolling with j ing from my invention. I prefer to form the their original rolling lines parallel. From tap of a number of intermediate laminae or these sheets so united properly shaped pieces 5 sheets 13 and 14, upon which is placed a indicated by the outermost outline in Fig.

thicker outside tap sole 15, preferably cor- 2 are constructed in any well'known man- I rugated, as shown, in a well known manner. ner. The sheets 13 and 14 are united in the In using a boot or shoe, the act of walking same manner as 11 and'12 with their original or running subjects the entire sole to re- 1 rolling lines parallel, and to this double ma- 30 peated bending strains or curves whose axis terial is united the outermost corrugated lies across the shoe or boot. Hitherto, where layer or layers 15 with'its or their line of soles were built up of separate sheets, they rolling at righ angles to those of the layers have been placed with the lines of rolling l3 and 14. T last named junction is of all the sheets across the shoe. Thereeffected by the cdl d' ro lling process above de- 35 salt has been. a very general tendency to scribed. From the material produced as last check or split across the sole. It is obvious above described properly shaped pieces to that the greater degree of bending will come form the taps are cut out, and these may in the lowermost layer 15 and therefore the be joined to the plain sole (composed of the arrangement of material should be such as to layers 11 and 12) by rolling cold, any grease 40 afford the llmXimllm t ty t this p rt or other impurity being first removed, prefof the sole. As I have pointed out above, erably by benzene. This completes the sole this is afforded by placing the line of rollwith the exception of applying the heel, ing across the solo at right angles, and I which can be accomplished. in any contherefore prefer to so place the corrugated venient way. The fabric produced as above 45 l y I have ver d, h w v r, h described is finally vulcanized in any manthe tendency to check or split which would ner appropriate to the particular use for otherwise exist in a layer so placed, may be which it is destined. overcome by uniting with the layer 15 other In my claims'the term, rubber applies layers as 11, 12, 13 and 1ft, whose lines of to any of th well known compounds to 5 rolling are longitudinal w th respect to the which that t rm i o mer iall a lied, sole. Broadly speaking thls may be accomcapable of treatment as above described, and plished in any suitable manner (including the Word sole, save when otherwise the use of cement) but I prefer the processes limited, covers whatever may be joined to described below. the uppers of a boot or shoe beneath the 55 The arrangement described affords the same, whether or not a tap or heel or both tensilestrength and the prevention of checkbe included. In In claims, the expression ing due to longitudinal lines of rolling, united integrally indicates union of adwhile also giving the elasticity in the under jacent sheets without the intervention of portion of the sole due to transverse lines. foreign material such as the benzene or other 60 Accordingly I have found that shoes and volatile constituent of rubber cement which boots provided with rubber soles made as. causes sponginess and consequent weakening above .described exhibit increased wearing of the fabric.

ualities without sensible diminution of What I claim is-- e asticity. Moreover tearingor splitting 1. The process of making rubber fabric 65 through the whole sole is entirely prevented. which consists in superposing a plurality of 1 sheets of calender-ed rubber so that the line of rolling of one or more of said sheets makes a material angle with that of another and uniting said sheets integrally, substantially as described.

2. The process of making rubber fabric which consists in superposing two sheets of rubber so that the line of rolling of one crosses that of the other and. vulcanizing said sheets together, substantially as described.

The process of making rubber fabric which consists in super-posing two sheets of calendered rubber so that the line of rolling of one crosses that of the other, rolling the two together in an imvulcai'iized condition while cold and then uniting the two by vulcanization, substantially as described.

4. The process of making rubber soles for boots or shoes which consists in forming a plain sole by super-posing and uniting sheets of rubber with the line of rolling parallel, forming a tap sole by super-posing and uniting sheets of rubber the line ot' rolliug of one or more of which makes a material angle with the line of rolling of others, and uniting said tap sole to said plain sole, substantially described.

5. The process of making rubber soles for boots and shoes which consists in forming a plain sole by rolling together sheets of uncured rubber with the line of rolling parallel, forming a tap solo by rolling together similar sheets placed with the line of rolling of one or more. making an angle with the line of rolling of others, uniting said tap sole to said plain sole and vulcanizing the whole, substantially as described.

(3. The process of making rubber soles for boots and shoes which consists in rolling a plurality of superposed sheets of uncured rubber with parallel lines of rolling while cold and cutting the resulting composite sheet into proper shape for the plain sole, rolling together other suitably shaped sheets of uncured rubber in a similar manner but with one sheetat least having its line of rolling placed at a material angle to the line of rolling of others, to form the tap sole, uniting said tap sole to said plain sole by cold rolling, and'vulcanizing the whole, substantially as described.

7. The process of making rubber soles for boots and shoes which consists in rolling a plurality of superposed sheets of uncured rubber with parallel lines of rolling while cold and cutting the resulting composite sheet into proper shapes for forming the plain sole and the intermediate layer of the. tap sole, uniting with said last named layer by cold rolling a suitably shaped outer tap sole having its line of rolling placed at a material angle to that of the other layers, to form a complete tap sole, uniting said complete tap sole to said plain sole by cold rolling, and vulcanizing the whole, substantially as described.

8. The process of making rubber soles for boots and shoes which consists in rolling together a number of uncured sheets of calem dered rubber with parallel lines of rolling, cutting therefrom suitably shaped pieces to form the inner portion of the sole with the lines of rolling ltmgitlulinal, super-posing thereon a suitably shaped tap sole comprising united layers of uncured calendcred rubber tying across the sole, uniting said tap sole to the remaining sheets by cold rolling under high pressure, and uniting the whole by vulcanization, substantially as described.

ADNA 1). WARNER. itnesses:

Il'. S. MAoKArn, M. A. llu'rnnn. 

